The present invention relates in general to radio frequency identification (RFID) devices, and more particularly to an RFID passive repeater system and apparatus.
RFID systems are well known in the art. Such systems include relatively large packages containing battery powered transmission/receiving circuitry, such as the identification system disclosed in U.S. Pat. No. 4,274,083, to passive systems in which the transceiver receives its power from the base station or interrogator, such as the identification system disclosed in U.S. Pat. No. 4,654,658.
A typical RFID system is made up of reusable tags fixed to or embedded in product carriers, antennas that interrogate the tags via a RF link and a controller. The host (or computer) system interfaces with the controller and directs the interrogation of the tags.
RFID tags provide effective means of identifying, monitoring and controlling materials in a closed loop process. In the factory, tags are employed as the transport mechanism between xe2x80x9cislands of automation,xe2x80x9d providing a record of each process which can be acted upon immediately or downloaded later for analysis.
The tags can be powered by an internal battery (i.e., an xe2x80x9cactivexe2x80x9d tag) or by inductive coupling (i.e., a xe2x80x9cpassivexe2x80x9d tag). Passive tags have zero maintenance and virtually unlimited life. The life span of an active tag is, however, limited by the lifetime of the battery, although some tags offer replaceable batteries. RFID tags also have limited applicability due to limitations on the operating range.
It is therefore an object of the present invention to provide a passive repeater system and apparatus having a least one passive loop (i.e., antenna) that effectively and efficiently extends the operating range of a conventional RFID tag.
It is another object of the invention to provide passive repeater system and apparatus that reduces orientation sensitivity of a conventional RFID tag.
In accordance with the above objects and those that will be mentioned and will become apparent below, the RFID passive repeater system in accordance with one embodiment of the invention preferably comprises a RFID reader having a magnetic flux field, at least one RFID tag and at least one passive repeater member having at least one substantially continuous passive loop, the passive loop being adapted and positionable with respect to the RFID reader and, tag to couple the reader and tag, the passive repeater member being further adapted and positionable with respect to the RFID reader and tag to redirect the magnetic flux field. In an alternative embodiment, the passive repeater member also extends the range of the magnetic flux field.
In a further embodiment of the invention, the RFID passive repeater system comprises a RFID reader having a magnetic flux field, at least one RFID tag and at least one passive repeater member having at least one substantially continuous passive loop, the passive loop being adapted and positionable with respect to the RFID reader and tag to couple the reader and tag, the passive repeater member being further adapted and positionable wit respect to the RFID reader and tag to extend the range of the magnetic flux field.
The passive repeater xe2x80x9cproduct containerxe2x80x9d system in accordance with one embodiment of the invention comprises a RFID reader having a magnetic flux field, at least one RFID tag disposed on at least one item contained in a product container, and at least one passive repeater member disposed on one of the product container panels having at least one substantially continuous passive loop, the passive loop being adapted and positionable with respect to the RFID reader and tag to couple the reader and tag, the passive repeater member being further adapted and positionable with respect to the RFID reader and tag redirect the magnetic flux field. In an alternative embodiment the passive repeater member also extends the range of the magnetic flux field.
In additional embodiments of the passive repeater xe2x80x9cproduct containerxe2x80x9d system, a passive loop is disposed directly on or embedded in at least one of the product container panels.
The passive repeater xe2x80x9cproduct carrierxe2x80x9d system in accordance with one embodiment of the invention comprises a RFID reader having a magnetic flux field, at least one RFID tag disposed on at least one product container or product contained in or disposed on a product carrier, and at least one passive repeater member, the passive repeater member having at least one substantially continuous passive loop, the passive loop being adapted and positionable with respect to the RFID reader and tag to couple the reader and tag, the passive repeater member being further adapted and positionable with respect to the RFID reader and tag redirect the magnetic flux field. In an alternative embodiment, the passive repeater member also extends the range of the magnetic flux field.
In additional embodiments of the passive repeater xe2x80x9cproduct carrierxe2x80x9d system a plurality of passive repeater members are disposed in the product carrier. In yet another embodiment of the passive repeater xe2x80x9cproduct carrierxe2x80x9d system a second passive loop is disposed on a wall of the product carrier.